This competitive renewal is aimed at securing funds for maintenance and management of a growing colony of dogs with canine narcolepsy. Our procedures will describe the genetic factors involved in the transmission of canine narcolepsy. The necessary breeding program implicit in achieving this goal could result in several strains of reliably reproducing narcoleptic dogs. We will document the various ramifications of the unique REM sleep related pathology exemplified by cataplexy and sleep onset REM periods both within individuals and across breeds as well as in "high risk" animals who show no obvious signs, or ambiguous signs, of clinical narcolepsy. Studies of pathological sleepiness in narcoleptic dogs and controls by means of continuous polygraphic recordings and multiple sleep latency tests will be carried out. We will begin a series of strategically designed pilot studies emphasizing biochemical approaches aimed at elucidating the specific CNS defect(s) that cause canine narcolepsy.